In the intimate missive, the legendary author addresses the screen star as "Dearest Kraut," imagines her "drunk and naked" and describes how he would approach her with "the physique of Burt Lancaster."

Dietrich and Hemingway first met aboard a cruise liner from Paris to New York in 1934 and became lifelong friends. They never became lovers, but their lengthy correspondence is full of mutual longing and affection.

The letter set for auction begins with Hemingway responding to Dietrich's complaints about the staging of a Las Vegas show she is starring in -- but it soon takes an abrupt turn toward the weird.

"If I were staging, it would probably have something novel, like having you shot onto the stage, drunk, from a self propelled minnenwerfer," he writes. "As you landed on the stage, drunk and naked I would advance from the rear, or your rear, wearing evening clothes and I would hurriedly strip off my evening clothes to cover you, revealing the physique of Burt Lancaster..."

He later mentions how the production would "employ reversed vacuum cleaners which would blow my evening clothes off you."

"This is the scene which is really Spine tingling and I have just the spine for it," he adds. "I play it with a Giant Rubber Whale called Captain Ahab… You are foaming at the mouth of course to show that we are really acting and we bottle the foam and sell it to any surviving customers."

The letter was written during the filming of John Sturges' adaptation of Hemingway's The Old Man and the Sea. He writes to Dietrich complaining about how he himself has been tasked with catching a big enough fish for the film's fishing scenes. "I only wrote the book but must do the work as well and have no stand-in. Up at 4:50 a.m., knock off at 7:30 p.m.," he writes.

The letter comes from a 250-piece collection of Dietrich's belongings that were left to her three grandchildren. The trove includes one of Dietrich's iconic black tuxedos, sunglasses, a typewriter, cigarette lighters, photographs, clocks and letters. The auction will be held from March 19 to April 6 on Auctionmystuff.com. Some of the items are currently being exhibited at the Hollywood Museum in Los Angeles prior to the sale.

Not anticipating its eventual sale by auction, of course, the Hemingway letter nonetheless concludes on an ironically moody and fatalistic note about the nature of celebrity: "I think you could say you and I have earned whatever dough the people let us keep. So what. So merde. I love you as always -- Papa."